Superior vena cava syndrome (SVCS) is a group of symptoms caused by the partial blockage or compression of the superior vena cava, the major vein that carries blood from the head, neck, upper chest, and arms to the heart. In most instances, SVCS is caused by cancer.

Causes

The superior vena cava, which drains into the right atrium (upper chamber) of the heart, can become compressed when a tumor growing inside the chest presses on the vein. The most likely types of cancer to cause SVCS are lung cancer and non-Hodgkin lymphoma, and other cancers that spread to the chest. Sometimes a tumor originally outside the superior vena cava may actually grow into, or invade, the vein causing a blockage. Because the superior vena cava lies close to a number of lymph nodes (tiny, bean-shaped organs that fight infection), any cancer that spreads to these lymph nodes, causing them to enlarge, can also cause SVCS. Enlarged lymph nodes compress the vein, which slows the blood flow and may result in complete blockage. A less common cause of SVCS is a thrombosis (blood clot) in the vein caused by an intravenous catheter or a pacemaker wire.

Symptoms

Symptoms usually develop slowly and include difficulty breathing or shortness of breath, coughing, and swelling of the face, neck, upper body, and arms. Rarely, patients may experience hoarseness, chest pain, difficulty swallowing, and coughing up blood.

Severe symptoms that are rarely seen include swelling of the veins in the chest and neck, fluid collection in the arms and face, and an increased rate of breathing. In severe instances, the skin may turn blue due to cyanosis (lack of oxygen). Also, in rare instances, the patient may experience paralysis of the vocal cords, and/or Horner's syndrome, characterized by a constricted pupil, sagging eyelid, and the absence of sweat on only one side of the face. SVCS can develop quickly to completely block the trachea (airway). When this occurs, a ventilator may be needed to help the patient breathe until the obstruction can be treated. More commonly, if the blockage develops slowly, other veins may enlarge to carry extra blood and symptoms may be milder.

Diagnosis and treatment

Signs of SVCS can be seen with a chest x-ray and other imaging techniques, such as chest computerized tomography (CT) scan or magnetic resonance imaging (MRI). However, these tests cannot diagnose SVCS. If symptoms are mild, the trachea is not blocked, and there is good blood flow through other veins in the chest, treatment may not begin until a clear diagnosis is made, or treatment may not be needed. In most cases, SVCS is managed by treating the underlying cancer with chemotherapy or radiation treatment directed at the mass causing the blockage. Other short-term treatments to reduce symptoms include raising the patient’s head, giving corticosteroids to reduce swelling, or using diuretics to eliminate excess fluid from the body. Less often, SVCS may be treated with thrombolysis (treatment to break up a blot clot in the vein), stent placement (a tube-like device inserted into the blocked area of the vein to allow blood to pass through), or surgery (to bypass a blockage caused by cancer).

Patient considerations

Because SVCS can cause serious breathing problems, it is considered an emergency. Learn about potential symptoms of SVCS and immediately report any symptoms to your doctor. Even though SVCS is serious and its symptoms can be frightening, it is successfully treated in most people.

SVCS in children

SVCS in children can be life threatening. Because a child's trachea is smaller and softer than an adult's, it can quickly swell or become constricted, causing breathing problems. Common SVCS symptoms in children are similar to those in adults and may include coughing, hoarseness, difficulty breathing, and chest pain. Fortunately, SVCS is rare in children.

More Information

Cancer.Net Guide to Lung Cancer

Cancer.Net Guide to non-Hodgkin Lymphoma

Managing Side Effects

Last Updated: April 30, 2009